Speculating about society after a singularity is pointless. It leads
to poorly thought-out ideas and is dominated by speculative wishful
thinking. A complete waste of time.

So, let's do it.

The aspect of a post-singularity world I'd like to look at is the
absence of signalling. If we had an advanced AI, it should be able to
fully understand the personality and abilities of an individual human.
If it would accept to reveal this information to humans, then we would
live in a society with perfect understanding of each other.

This would negate the need for signaling - people would no longer be
driven to art, education, competitive sports, positional goods, and
other ways of showing off. A good proportion of the current economy
and culture would vanish.

Also, other types of economy and governments would be viable (if they
still exist). Benevolent dictators might become the best system of
government; utopian communes would be successful, stable social
organisms; friendship as the main social link would decay.

The more serious question is whether we want this AI-modulated
empathy, or would prefer some remnants of signalling.